JP2010185933A - Optical instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the abrasion powder generated in a vibration motor from flying around. <P>SOLUTION: An optical instrument has first cylinders 204, 206 and a second cylinder 205 provided inside the first cylinder, both composing the lens barrel; a vibrator 2A3 arranged in the lens barrel between the first cylinder and the second cylinder and vibrated by the electrical-mechanical energy convertor element; a vibration motor including a rotor 2A6 turning in contact with the vibrator; and a dust proofing component 2A11 which is arranged at a position facing the contact area of the vibrator and the rotor inside the lens barrel and having an outermost diameter D1 larger than the innermost diameter D2 of the contact area. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical apparatus having a lens barrel provided with a vibration type motor.

Some optical devices such as an interchangeable lens and a lens-integrated camera move a lens by a vibration type motor called a vibration wave motor or an ultrasonic motor (see Patent Document 1).
The vibration type motor includes a vibrating body (elastic body) whose vibration is excited by an electro-mechanical energy conversion element (piezoelectric element) and a rotating body that rotates in contact with the vibrating body.

JP-A-2-253215

However, in the vibration type motor, since the vibrating body and the rotating body are in contact with each other in a pressurized state, wear occurs at the contact portion between the vibrating body and the rotating body, thereby generating wear powder. If this wear powder scatters to the mechanism in the optical device (especially the lens barrel) or the position detector that detects the position of the lens, the mechanism operates smoothly and the position detector (especially on the substrate on which the conductive pattern is formed). May prevent accurate position detection by a brush sliding type).
The present invention provides an optical apparatus capable of suppressing the scattering of wear powder generated from a vibration type motor.

An optical apparatus according to an aspect of the present invention is a cylindrical member that constitutes a lens barrel, and includes a first cylindrical member, a second cylindrical member disposed inside the first cylindrical member, A vibrating body that is disposed in an in-cylinder region between the first and second cylindrical members and is excited by an electro-mechanical energy conversion element, and a rotating body that rotates in contact with the vibrating body And a vibration type motor including the contact portion between the vibrating body and the rotating body in the inner region of the lens barrel, the outermost diameter being larger than the innermost diameter of the contact portion. And a dustproof member.

  According to the present invention, the dust-proof member having the outermost diameter larger than the outermost inner diameter of the contact portion between the vibrating body and the rotating body is effective in scattering the abrasion powder generated at the contact portion into the region in the lens barrel. Can be suppressed.

1 is a diagram illustrating a schematic configuration of an interchangeable lens that is an embodiment of the present invention and a camera equipped with the interchangeable lens. FIG. FIG. 2 is a block diagram showing an electrical configuration of the interchangeable lens and camera shown in FIG. 1. Sectional drawing which shows the structure of the interchangeable lens of an Example. The disassembled perspective view of a part of the interchangeable lens. The figure which expanded a part of sectional drawing shown in FIG. The figure which expanded a part of sectional drawing shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of an interchangeable lens as an optical apparatus according to an embodiment of the present invention and a single-lens reflex digital still camera (imaging device) to which the interchangeable lens is attached. Reference numeral 1 denotes a single-lens reflex digital still camera (hereinafter referred to as a camera), and reference numeral 2 denotes a zoom optical system provided in the interchangeable lens 200. The zoom optical system 2 has a plurality of lens units described later. An anti-vibration driving unit 3 drives the anti-vibration lens unit 12 included in the zoom optical system 2 in a direction perpendicular to the optical axis 4 of the zoom optical system 2. Reference numeral 5 denotes a lens barrel that accommodates the zoom optical system 2. The lens barrel 5 and the zoom optical system 2 constitute an interchangeable lens 200 as a zoom lens device. The interchangeable lens 200 can be attached to and detached from the camera 1.
In the camera 1, reference numeral 6 denotes an image sensor such as a CCD sensor or a CMOS sensor that photoelectrically converts a subject image formed by the zoom optical system 2. Reference numeral 7 denotes a memory for storing image data generated based on the output from the image sensor 6. Reference numeral 8 denotes a shake sensor that detects camera shake such as camera shake, and reference numeral 9 denotes a focus drive unit that drives a focus lens unit included in the zoom optical system 2.
Reference numeral 10 denotes a power source of the camera 1 (and the interchangeable lens 200), and 11 denotes a release button. Reference numeral 13 denotes a quick return mirror, and reference numeral 14 denotes a finder optical system.
FIG. 2 shows an electrical configuration of the camera 1 and the interchangeable lens 200. The camera 1 has an imaging system, an image processing system, a recording / reproducing system, and a control system.
The imaging system is composed of an imaging element 6. The image processing system includes an A / D converter 20 and an image processing circuit 21. The recording / reproducing system includes a recording processing circuit 23 and a memory 24. The control system includes a camera system control circuit 25, an AF sensor 26, an AE sensor 27, a shake sensor 8, and an operation detection circuit 29. The interchangeable lens includes a lens system control circuit 30.
The image processing circuit 21 performs various processes such as white balance, gamma correction, and interpolation calculation on the output signal received from the image sensor 6 via the A / D converter 20 to generate image data. The recording processing circuit 23 performs recording processing of image data in the memory 24 and generates an image to be output to the display unit 22 configured by a liquid crystal monitor or the like.
The operation detection circuit 29 detects an operation of an operation member such as the release button 11 and sends an operation detection signal to the camera system control circuit 25. The camera system control circuit 25 controls each part in the camera 1 and the interchangeable lens according to the operation detection signal.
The AF sensor 26 detects the focus state of the interchangeable lens. The AE sensor 27 detects the luminance of the subject. The shake sensor 8 detects camera shake. The camera system control circuit 25 outputs to the lens system control circuit 30 signals for controlling the focusing, aperture, and image stabilization operations based on signals from the AF sensor 26, the AE sensor 27, and the shake sensor 8. The lens system control circuit 30 controls the focus drive unit 9, the aperture drive unit (not shown), and the image stabilization drive unit 3 in accordance with a signal from the camera system control circuit 25.
Next, the configuration of the interchangeable lens 200 will be described with reference to FIGS. 3 and 4. FIG. 3 shows a cross-sectional structure when the interchangeable lens 200 is cut along a plane passing through the optical axis 4. FIG. 4 shows a part of the interchangeable lens 200 in an exploded manner.
The interchangeable lens 200 has a mount 201 for detachably mounting on the camera 1. The mount 201 is provided with a connector for communication between the camera 1 and the interchangeable lens 200. The mount 201 is attached to the base cylinder 203 with screws. An intermediate cylinder 204 is fixed to the base cylinder 203 with screws.
The intermediate cylinder 204 is attached to the guide cylinder 205 with screws. An outer ring 206 is attached to the intermediate cylinder 204 with screws. The guide cylinder 205 (and the intermediate cylinder 204) corresponds to a fixed cylinder that does not move during zooming and focus adjustment.
A first lens holding cylinder (lens holding member) 207 holding a first lens unit (fixed lens) L1 is supported on the most object side (left side in the drawing) of the guide cylinder 205.
The first lens unit L1 held by the first lens holding cylinder 207 is disposed on the object side (most object side among the plurality of lens units) with respect to a second lens unit (focus lens unit) L2 described later. It does not move during zooming and focusing.
However, an eccentric cam follower 210 is attached to the first lens holding cylinder 207 with a screw. As shown in FIG. 3, the eccentric cam follower 210 includes a shaft portion 210A that is inserted into a hole formed in the outer peripheral surface of the first lens holding cylinder 207, and an eccentric follower portion 210B that is eccentric with respect to the shaft portion 210A. Have The eccentric follower portion 210B is engaged with a position adjusting cam groove (adjusting groove) 205B formed in the guide tube (supporting tube) 205.
When the interchangeable lens 200 is assembled, when the first lens holding cylinder 207 is rotated around the optical axis, the eccentric cam follower 210 moves along the position adjusting cam groove 205B. Thereby, the position in the optical axis direction of the first lens holding cylinder 207 with respect to the guide cylinder 205 can be adjusted.
When the eccentric cam follower 210 is rotated about the axis of the shaft portion 210A, the guide tube 205 (that is, another lens) of the first lens holding tube 207 is caused by the eccentric rotation of the eccentric follower portion 210B in the position adjusting cam groove portion 205B. The tilt angle with respect to the optical axis of the unit changes. Thereby, the tilt angle of the first lens holding cylinder 207 with respect to the guide cylinder 205 can be adjusted.
Then, the first lens holding cylinder 207 is fixed to the guide cylinder 205 using the screw base 228 and the screw 229.
A main cam cylinder (rotating cylinder) 208 is arranged inside the guide cylinder 205. A cam follower (not shown) is attached to the main cam cylinder 208 with screws. The cam follower is engaged with a groove 205 </ b> A formed to extend in the circumferential direction on the inner periphery of the guide cylinder 205. Therefore, the main cam cylinder 208 does not move in the optical axis direction with respect to the guide cylinder 205 (that is, at a fixed position in the optical axis direction) and can rotate around the optical axis. The main cam cylinder 208 is formed with a fourth cam groove 208B.
A sub cam cylinder (cam cylinder) 209 is disposed inside the main cam cylinder 208. A cam follower (second cam follower) C shown in FIG. 4 is attached to the sub cam cylinder 209 with screws. As shown in FIG. 4, the cam follower C includes a rectilinear groove portion (second rectilinear guide portion) 208A provided in the main cam cylinder 208 so as to extend in the optical axis direction, and a sub cam groove portion (second cam) provided in the guide cylinder 205. Part) 205D. Therefore, when the main cam cylinder 208 rotates, the sub cam cylinder 209 rotates around the optical axis together with the main cam cylinder 208 and moves in the optical axis direction with respect to the main cam cylinder 208. The sub cam cylinder 209 is provided with a focus cam groove portion (first cam portion) 209B.
Inside the sub cam cylinder 209, a third lens rectilinear guide cylinder (second rectilinear guide cylinder) 214 is arranged. As shown in FIG. 4, the convex portion 211A of the second lens rectilinear guide tube 211 and the groove portion 209A of the sub cam tube 209 are bayonet-coupled. Therefore, the second lens rectilinear guide tube 211 can move in the optical axis direction together with the sub cam tube 209 and can rotate around the optical axis with respect to the sub cam tube 209.
As shown in FIG. 4, the second lens rectilinear guide tube 211 is provided with a rectilinear groove portion (first rectilinear guide portion) 211B and a focus key groove portion 211C that extend in the optical axis direction. A focus key 2A2 of a focus drive unit (focus drive mechanism) 2A, which will be described later, engages with the focus key groove 211C in the direction around the optical axis.
Inside the second lens rectilinear guide tube 211, a second lens holding tube (focus lens holding tube) 212 holding the second lens unit L2 that is a focus lens unit is disposed. A cam follower (first cam follower) 213 is attached to the outer periphery of the second lens holding cylinder 212 with screws. The cam follower 213 is engaged with a focus cam groove portion 209 </ b> B provided in the sub cam cylinder 209 and a rectilinear groove section 211 </ b> B provided in the second lens rectilinear guide cylinder 211.
Inside the sub cam cylinder 209, a third lens rectilinear guide cylinder (second rectilinear guide cylinder) 214 is arranged. A groove 214A formed so as to extend in the circumferential direction on the outer periphery of the third lens rectilinear guide tube 214 and a convex portion 209B formed on the inner periphery of the sub cam tube 209 are bayonet-coupled. Thus, the third lens rectilinear guide tube 214 can move in the optical axis direction together with the sub cam tube 209 and can rotate around the optical axis with respect to the sub cam tube 209.
The third lens rectilinear guide tube 214 has a rectilinear groove portion (third rectilinear guide portion) 214B and a rectilinear guide key groove portion 214C extending in the optical axis direction. A rectilinear guide key (rotation prevention member) 216 engages with the rectilinear guide key groove 214C in the direction around the optical axis.
Inside the third lens rectilinear guide tube 214, a third lens holding tube 215 that holds the third lens unit L3 adjacent to the second lens unit L2 in the optical axis direction (image side) is disposed. .
A cam follower (third cam follower) E is attached to the outer periphery of the third lens holding cylinder (magnifying lens holding cylinder) 215 with screws. The cam follower E is engaged with a zoom cam groove part (third cam part) 209D provided in the sub cam cylinder 209 and a rectilinear groove part 214B provided in the third lens rectilinear guide cylinder 214.
Here, the sub cam cylinder 209 has a first cylinder part 209E on the object side, and a second cylinder part 209F having a smaller inner and outer diameter than the first cylinder part 209E on the image side. The second lens unit L2 and the second lens holding cylinder 212 that holds the second lens unit L2 are disposed inside the first cylinder portion 209E. The third lens unit L3 and the third lens holding cylinder 215 that holds the third lens unit L3 are disposed inside the second cylinder portion 209F.
A straight guide key 216 is fixed to the guide tube 205. As described above, the rectilinear guide key 216 is engaged with the rectilinear guide key groove 214C of the third lens rectilinear guide tube 214.
A cam follower 218 is attached to the outer periphery of the fourth lens holding cylinder 217 holding the fourth lens unit L4 with screws. As shown in FIG. 4, the cam follower 218 is engaged with a fourth cam groove 208 </ b> B provided on the main cam cylinder 208 and a rectilinear groove 205 </ b> E provided on the inner periphery of the guide cylinder 205.
A zoom operation ring (zoom operation member) 219, a gear ring 220 attached to the zoom operation ring 219 with a screw, and a zoom lever, which will be described later, are attached to the outside of the intermediate cylinder 204, and rotate around the outer periphery of the intermediate cylinder 204 Possible gear rings 221 are arranged. The zoom operation ring 219, the gear ring 220, and the gear ring 221 are rotatable around the optical axis at a fixed position in the optical axis direction with respect to the intermediate cylinder 204. Further, a rolling gear unit 222 is disposed between the gear ring 220 and the gear ring 221, and the gear unit 222 is coupled to the intermediate cylinder 204 with a screw.
One end of the zoom lever 223 is attached to the gear ring 221 with a screw. The other end of the zoom lever 223 is engaged with the main cam cylinder 208 in the direction around the optical axis.
A focus operation ring (focus operation member) 224 is disposed outside the guide tube 205. A cam follower 205G attached to the outer periphery of the guide tube 205 with a screw is engaged with a groove 224A provided on the inner periphery of the focus operation ring 224. For this reason, the focus operation ring 224 can rotate around the optical axis at a fixed position in the optical axis direction outside the guide tube 205.
The focus operation ring 224 is coupled to the fixed position rotation ring 2A1 in the focus drive unit 2A. For this reason, the rotational force of the focus operation ring 224 can be transmitted to the focus drive unit 2A.
The focus drive unit 2A incorporates a differential operation mechanism. The rotational force output from the differential operation mechanism is transmitted to the second lens rectilinear guide tube 211 via the focus key 2A2 engaged with the focus key groove 211C of the second lens rectilinear guide tube 211, and rotates it.
On the image side of the fourth lens holding cylinder 217, an electric aperture unit 2C is disposed. A fifth lens holding cylinder 225 that holds the fifth lens unit L5 is disposed on the image side of the electric aperture unit 2C. The fifth lens holding cylinder 225 is disposed inside the intermediate cylinder 204. A follower (not shown) is attached to the outer periphery of the fifth lens holding cylinder 225, and the follower is engaged with a hole (not shown) formed in the inner periphery of the intermediate cylinder 204. For this reason, the fifth lens holding cylinder 225 is held at a fixed position in the optical axis direction with respect to the intermediate cylinder 204.
The sixth lens unit L6 corresponds to the anti-vibration lens unit 12 shown in FIGS. The anti-vibration unit 2B includes a sixth lens holding cylinder 226 that holds the sixth lens unit L6, and two sets for moving the sixth lens holding cylinder 226 in two directions orthogonal to the optical axis and orthogonal to each other. And an anti-vibration actuator (magnet and coil). Further, the image stabilization unit 2B includes a position detection element that detects the position of the sixth lens holding cylinder 226, and a drive control board that controls the image stabilization actuator using a signal from the position detection element. The anti-vibration driving unit 3 in FIGS. 1 and 2 is configured by the anti-vibration actuator, the position detection element, and the drive control board.
A cam follower (not shown) that engages with a hole (not shown) formed on the inner periphery of the intermediate cylinder 204 is attached to the outer periphery of the vibration isolation unit 2B. Accordingly, the image stabilization unit 2B is held at a fixed position in the optical axis direction with respect to the intermediate tube 204.
A seventh lens holding cylinder 227 holding a seventh lens unit L7, which is the most image side lens unit, is fixed to the image side end of the intermediate cylinder 204 with a screw. An angular velocity sensor (gyro sensor) corresponding to the shake sensor 8 shown in FIGS. 1 and 2 is attached to the seventh lens holding cylinder 227. The seventh lens holding cylinder 227 is attached with two control boards on which the lens system control circuit 30 shown in FIG. 2 is configured.
Next, an operation when the zoom operation ring 219 is operated at the time of zooming in the interchangeable lens 200 configured as described above will be described. In the following description, rotating around the optical axis is simply referred to as “rotating”, and moving in the optical axis direction is referred to as “going straight”.
When the zoom operation ring 219 is rotated, the gear ring 220 is rotated and the gear ring 221 is rotated via the gear unit 222. The rotational force of the gear ring 221 is transmitted to the main cam cylinder 208 via the zoom lever 223 and rotates it. The rotation direction of the main cam cylinder 208 is opposite to the rotation direction of the zoom operation ring 219. As described above, the main cam cylinder 208 rotates with respect to the guide cylinder 205 at a fixed position in the optical axis direction.
When the main cam cylinder 208 rotates, the sub cam cylinder 209 having the cam follower C engaged with the rectilinear groove portion 208 </ b> A of the main cam cylinder 208 rotates the same amount as the main cam cylinder 208. Since the cam follower C is also engaged with the sub cam groove 205 </ b> D of the guide cylinder 205, the sub cam cylinder 209 advances straight with respect to the main cam cylinder 208. That is, the sub cam cylinder 209 advances straight with respect to the main cam cylinder 208 while rotating.
A rotational force acts on the second lens rectilinear guide cylinder 211 that is bayonet-coupled to the sub cam cylinder 209 due to friction of the bayonet-coupled portion. However, the focus key 2A2 of the focus drive unit 2A is engaged with the focus key groove 211C of the second lens rectilinear guide tube 211. The focus key 2A2 is held so as not to rotate by a friction holding force (a friction holding force larger than the friction of the bayonet coupling portion) in the differential operation mechanism of the focus drive unit 2A. For this reason, the rotation of the second lens rectilinear guide tube 211 is prevented.
As described above, the second lens holding cylinder 212 has the cam follower 213 engaged with the focus cam groove 209B of the sub cam cylinder 209 and the rectilinear groove 211B of the second lens rectilinear guide cylinder 211. Therefore, when the sub cam cylinder 209 rotates while moving straight, the second lens holding cylinder 212 moves straight with respect to the sub cam cylinder 209 and the second lens linear guide cylinder 211 without rotating.
Further, a rotational force acts on the third lens rectilinear guide cylinder 214 that is bayonet-coupled to the sub cam cylinder 209 due to friction of the bayonet-coupled portion. Further, while the sub cam cylinder 209 rotates straight with respect to the main cam cylinder 208, a rotational force acts on the third lens rectilinear guide cylinder 214 from the sub cam cylinder 209 due to friction at the fitting portion with the main cam cylinder 208. To do. However, the rectilinear guide key groove 216 of the third lens rectilinear guide tube 214 is engaged with the rectilinear guide key 216 fixed to the guide tube 205. For this reason, the third lens rectilinear guide cylinder 214 moves straight along with the sub cam cylinder 209 in a state where rotation is blocked.
As described above, the third lens holding cylinder 215 has the cam follower E engaged with the zoom cam groove 209D of the sub cam cylinder 209 and the rectilinear groove 214B of the third lens rectilinear guide cylinder 214. Therefore, when the sub cam cylinder 209 rotates while going straight, the third lens holding cylinder 215 goes straight with respect to the sub cam cylinder 209 and the third lens rectilinear guide cylinder 214 without rotating. For this reason, the movement amount of the third lens holding cylinder 215 in the optical axis direction is larger than the movement amount of the sub cam cylinder 209 in the optical axis direction.
On the other hand, when the main cam cylinder 208 rotates, the fourth lens holding cylinder 217 having the cam follower 218 engaged with the fourth cam groove 208B of the main cam cylinder 208 and the rectilinear groove (not shown) on the inner periphery of the guide cylinder 205 rotates. Without going straight, it goes straight with respect to the main cam cylinder 208.
As described above, when the zoom operation ring 219 is rotated, the second, third, and fourth lens holding cylinders 212, 215, and 217 move straight, and the magnification (focal length) of the interchangeable lens 200 (zoom optical system 2) is increased. Change).
Next, an operation when the focus operation ring 224 is operated during focus adjustment will be described.
When the focus operation ring 224 is rotated, the rotational force rotates the second lens rectilinear guide tube 211 via the differential operation mechanism of the focus drive unit 2A and the focus key 2A2. At this time, the main cam cylinder 208 and the sub cam cylinder 209 do not rotate.
When the second lens rectilinear guide tube 211 rotates, the second lens holding tube 212 having the cam follower 213 engaged with the focus cam groove portion 209B of the sub cam tube 209 and the rectilinear groove portion 211B of the second lens rectilinear guide tube 211 moves straight while rotating. To do.
As described above, when the focus operation ring 224 is rotated, the second lens holding cylinder 212 moves straight, and the focus adjustment of the interchangeable lens 200 (zoom optical system 2) becomes possible.
Next, an autofocus operation when the focus drive unit 2A operates according to an autofocus signal from the camera 1 will be described.
The focus drive unit 2A includes a vibration type motor. The configuration of the vibration type motor will be described later. When receiving an autofocus signal from the camera 1, the control board 230 drives the vibration type motor.
The rotational force of the vibration type motor rotates the focus key 2A2 via the differential operation mechanism, and rotates the second lens linear guide tube 211 via the focus key 2A2. At this time, the main cam cylinder 208 and the sub cam cylinder 209 do not rotate.
When the second lens rectilinear guide tube 211 rotates, the second lens holding tube 212 having the cam follower 213 engaged with the focus cam groove portion 209B of the sub cam tube 209 and the rectilinear groove portion 211B of the second lens rectilinear guide tube 211 moves straight while rotating. To do.
Thus, by operating the focus drive unit 2A, the second lens holding tube 212 moves straight, and the interchangeable lens 200 (zoom optical system 2) can be autofocused.
5A and 6 are enlarged views of a part of the cross-sectional view of the interchangeable lens (lens barrel) shown in FIG. 3, and in particular, the configuration of the focus drive unit 2A is shown in detail.
The focus drive unit 2A is provided with the above-described vibration type motor. 2A3 is a ring-shaped stator (vibrating body) having a trapezoidal cross section perpendicular to the circumferential direction. 2A4 is a piezoelectric element as an electro-mechanical energy conversion element joined to one end face (right end face in FIGS. 5 and 6) of the stator 2A3. 2A5 is a ring-shaped vibration absorber made of felt or the like attached to the back surface of the piezoelectric element 2A4.
2A6 is a rotor (rotating body), and 2A7 is a disc spring for bringing the stator 2A3 into pressure contact with the rotor 2A6. 2A8 is a pressure adjusting ring that is pressed by an inclined portion formed on the outer peripheral surface of the guide tube 205.
The ring-shaped vibration type motor constituted by the above components is arranged on the inner cylinder 204 and the outer ring 206, which are the first cylinder members constituting the lens barrel, respectively, and the inner circumference of the first cylinder member. In addition, it is arranged in a region in the lens barrel between the guide tube 205 as the second tube member. More specifically, they are arranged side by side in the optical axis direction (rotational axis direction of the vibration type motor).
In the lens barrel region, 2A9 is a connecting ring that rotates integrally with the rotor 2A6. Between the rotor 2A6 and the communication ring 2A9, a rubber ring 2A10 is arranged so as not to transmit vibration in the rotation axis direction from the rotor 2A6 side to the communication ring 2A9 side.
Furthermore, 2A11 is a dustproof ring in the region in the lens barrel. The inner periphery of the dustproof ring 2A11 is supported by the guide tube 205. A plurality of protrusions are formed on the outer periphery of the rear portion of the dust-proof ring 2A11, and the plurality of protrusions are inserted into a plurality of grooves of the stator 2A3 formed in a comb shape, and function as a rotation stop member of the stator 2A3. To do. In other words, the dust-proof ring 2A11 is configured by forming a dust-proof rib (dust-proof portion) 2A11a, which will be described later, on a rotation preventing member for a stator that has also been used in conventional optical equipment. The dustproof ring 2A11 or the dustproof rib 2A11a of the dustproof ring 2A11 corresponds to a “dustproof member”.

  The rotor 2A6, the rubber ring 2A10, and the connecting ring 2A9 are configured to rotate integrally with each other, and the rotor 2A6, the rubber ring 2A10, and the connecting ring 2A9 are optically driven by circumferential traveling wave vibration generated in the stator 2A3. Rotate around the axis.

  The pressure adjusting ring 2A8 also has a function of adjusting the contact pressure between the stator 2A3 and the rotor 2A6 by adjusting the elastic force of the disc spring 2A7.

  The communication ring 2A9 supports the rotor 2A6 and the rubber ring 2A10 on the rear end surface side, and is in contact with the outer peripheral surface of the roller 2A12 shown in FIG. 6 on the front end surface. At least three rollers 2A12 are provided in the circumferential direction. These rollers 2A12 are supported by a roller ring 2A13 so as to be rotatable around an axis orthogonal to the optical axis. The roller ring 2A13 is arranged on the outer periphery of the guide tube 205.

  The above-described fixed-position rotating ring 2A1 is supported so as to be rotatable around the optical axis via a fixing ring 2A14 supported by the guide cylinder 205. The fixed position rotating ring 2A1 is in contact with the roller 2A12 by the roller ring 2A13.

  The focus key 2A2 shown in FIG. 4 is fixed to the roller ring 2A13, and prevents the roller ring 2A13 from rotating around the optical axis through an opening formed in the guide tube 205.

Next, a differential operation mechanism that transmits driving force from the vibration type motor in the focus drive unit 2A will be described.
When a frequency signal such as a pulse signal is input to the piezoelectric element 2A4, progressive vibration is excited in the stator 2A3 by the action of the piezoelectric element 2A4. As a result, the rotor 2A6 that contacts the stator 2A3, the communication ring 2A9, and the rubber ring 2A10 are integrated and rotate around the optical axis. When the communication ring 2A9 is rotated, a force for rotating the contact ring 2A9 is applied to the roller 2A12 in contact therewith.

  Since the fixed position rotating ring 2A1 is held by friction with the end face of the fixed ring 2A14, the roller 2A12 rolls on the end face of the fixed position rotating ring 2A1. As a result, the roller ring 2A13 supporting the roller 2A12 rotates around the optical axis. The rotation amount of the roller ring 2A13 is ½ times the rotation amount of the rotor 2A6. Then, the focus key 2A2 that rotates integrally with the roller ring 2A13 rotates the second lens rectilinear guide tube 211 as described above.

As shown in FIG. 6, on the inner peripheral surface of the guide tube 205, a flexible printed circuit board 2A15 on which a conductive pattern for detecting the position in the optical axis direction of the second lens unit L2 moving in the lens barrel is formed. Is attached. A brush 2A16 that slides on the surface of the flexible printed board 2A15 is fixed to the roller ring 2A13. The flexible printed circuit board 2A15 and the brush 2A16 constitute a position detector that detects the position of the second lens unit L2 in the optical axis direction, and the position detector is disposed in the above-described lens barrel inner region.
When the focus driving unit 2A (that is, a vibration type motor) is driven, the contact surfaces of the stator 2A3 and the rotor 2A6 that are in contact with each other in a pressurized state are abraded and wear powder is generated. The amount of wear powder depends on the rubbing time, that is, the rotational speed of the rotor 2A6. For example, if AF by low-speed driving is continued for a long time, a large amount of wear powder may be generated.

Therefore, in this embodiment, as shown in detail in FIG. 5B, dust-proof ribs (convex parts extending in the circumferential direction) 2A11a as dust-proof parts are formed on the outer periphery of the dust-proof ring 2A11.
Here, in FIG. 5B, 2A6a is a ring-shaped main body (hereinafter referred to as a rotor main body) of the rotor 2A6. 2A6b is a contact piece portion having a spring property extending in the inner circumferential direction from the rear end portion of the rotor body 2A6a. The contact piece 2A6b is provided for the reason of absorbing the unevenness of the surface of the stator 2A3 and the axial displacement of the stator 2A3 by the spring property and ensuring stable rotation of the rotor 2A6. The tip of the contact piece 2A6b contacts the surface of the stator 2A3. The innermost diameter of the contact portion (contact region) between the tip of the contact piece 2A6b and the surface of the stator 2A3 is D2.

The dust-proof rib 2A11a is disposed at a position opposite to the stator 2A3 in the optical axis direction with respect to the contact portion between the stator 2A3 and the rotor 2A6 in the above-described region in the lens barrel. And the outermost diameter D1 of dustproof rib 2A11a is set larger than the innermost diameter D2 of a contact part. Thereby, it is possible to suppress the abrasion powder from being scattered in a region opposite to the stator 2A3 (region ahead of the dust-proof rib 2A11a) with respect to the dust-proof rib 2A11a in the region in the lens barrel.
A position detector composed of the flexible printed circuit board 2A15 and the brush 2A16, a driving force transmission mechanism composed of the communication ring 2A9, the roller ring 2A13, and the like are disposed in the region in front of the dust-proof rib 2A11a in the lens barrel region. ing. Therefore, the dust-proof rib 2A11a can prevent wear powder from being scattered on the position detector and the driving force transmission mechanism, thereby preventing the position detection accuracy from being lowered and preventing smooth driving force transmission.

  In addition, a recess 2A6c is formed in the inner peripheral portion of the rotor 2A6 so that the rotor main body 2A6a and the contact piece 2A6b constitute an inner peripheral surface and inner end surfaces before and after the optical axis direction in the circumferential direction. The dust-proof rib 2A11a is disposed inside the recess 2A6c. Thereby, even if the outermost diameter of the dust-proof rib 2A11a is increased, the outer diameter of the vibration type motor is not affected, and an increase in the diameter of the focus drive unit 2A or the lens barrel can be avoided.

  In addition, you may apply | coat an adhesive material to the outer peripheral surface of dust-proof ring 2A11. By adsorbing the wear powder with the adhesive, it is possible to more effectively suppress the scattering of the wear powder.

  Further, as shown in FIG. 5A, an adjustment hole 205 </ b> C used for assembling the interchangeable lens 2 is formed in the peripheral wall of the guide tube 205. The dust-proof rib 2A11a is disposed between the contact portion between the stator 2A3 and the rotor 2A6 and the adjustment hole 205C in the optical axis direction. Accordingly, it is possible to avoid wear powder from entering the inside of the guide tube 205 through the adjustment hole 205C and adhering to the lens (the fourth lens unit L4 or the third lens unit L3).

  The embodiments described above are merely representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

  For example, in the above embodiments, the interchangeable lens has been described. However, the present invention can also be applied to an optical apparatus such as a lens-integrated digital still camera or video camera.

An optical device that effectively suppresses the abrasion powder generated at the contact portion from scattering into the lens barrel region by a dustproof member having an outermost diameter larger than the innermost diameter of the contact portion between the vibrating body and the rotating body. Can be realized.

2A Focus Drive Unit 2A1 Fixed Position Rotating Ring 2A2 Focus Key 2A3 Stator 2A4 Piezoelectric Element 2A6 Rotor 2A7 Belleville Spring 2A9 Connection Ring 2A11 Dustproof Ring 2A12 Roller 2A13 Roller 2A15 Flexible Printed Circuit Board 2A16 Brush 2B Vibration Isolation Unit 2C Aperture Unit 203 Base Tube 204 Intermediate Tube 205 Guide tube 206 Exterior ring 208 Main cam tube 209 Sub cam tube

Claims (5)

Each of which is a cylindrical member that constitutes a lens barrel, a first cylindrical member, and a second cylindrical member disposed on the inner periphery of the first cylindrical member;
A vibration body that is disposed in an in-cylinder region between the first cylinder member and the second cylinder member and that is excited by an electro-mechanical energy conversion element, and rotates in contact with the vibration body A vibration type motor including a rotating body;
A dust-proof member disposed on the opposite side of the vibrating body with respect to a contact portion between the vibrating body and the rotating body in the lens barrel inner region and having an outermost diameter larger than an outermost inner diameter of the contact portion; An optical apparatus characterized by that. A concave portion extending in the circumferential direction is formed in the inner peripheral portion of the rotating body,
The optical apparatus according to claim 1, wherein the dustproof member is disposed inside the recess.   The position detection means for detecting the position of the lens moving in the lens barrel is disposed on the opposite side of the vibrating body from the dust-proof member in the lens barrel inner region. The optical apparatus according to 1. An opening is formed in the peripheral wall of the second cylindrical member,
The optical apparatus according to claim 1, wherein the dust-proof member is disposed between the contact portion and the opening. A rotation stopping member for preventing rotation of the vibrating body with respect to the second cylindrical member;
5. The optical apparatus according to claim 1, wherein the dust-proof member is a member in which a dust-proof portion is formed on the rotation stop member.